Brake



Jan. 14, 1941.

G. c. R. KUIPER BRAKE Original Filed Aug. 29, 1936 3 Sheets-Sheet 1 NM; w m m/ a Z Y Jan. 14, 1941.

G. C. R KU IPER BRAKE Original Filed Au 29, 1.956

3 Sheets-Sheet 3 INVENTOR. GEE/WED GB. 411/1 5? ATTORNEY.

Patented .Ian. 14, 1941 PATENT OFFICE BRAKE Gerhard C. R. Kuiper, Wiesbaden, Germany, as-

signor to The Midland Steel Products Company, Cleveland, Ohio, a. corporation of Ohio Original application August 29, 1936, Serial N6. Divided and this application February 10, 1939, Serial No. 255,678

- 8 Claims.

This application is a division of my copending application for Brakes, Serial No. 98,550 filed August 29, 1936, issued Oct. 3, 1939 as Patent No. 2,174,921 and relates to new and useful improvements in vehicle brakes and an object of the invention is to provide a brake system controlled by the energization and de-energization of the stop signal lamp circuit of the vehicle.

Another object of the invention is to provide a brake system including hydraulic brakes and vacuum brakes, the latter being controlled by the vehicle stop signal circuit actuated by the hydraulic brake mechanism. g

Another object is to provide ahousing mounted on the brake apron for pivotally supporting a lever connected to the center pin of a toggle brake mechanism and to the brake operating cable supported by the housing normal to the brake drum.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the accompanying drawings forming a part of the description and wherein like numerals are employed to designate like parts throughout the several views.

Fig. 1 is a layout of one embodiment of the invention,

Fig. 2 is a sectional view partly in elevation of the brake cables and power cylinder hookup sup ported on the axle of the vehicle,

- Fig. 3 is a sectional view of the power cylinder for moving the brake cables,

Fig. 4 is a sectional view of the control valve mechanism,

Fig. 5 is a layout of another embodiment of the invention,

Fig.6 is a sectional view power cylinder.

Referring to Figs. 1 through 4, the numeral I0 designates a hydraulic master cylinder provided with a piston H actuated by a brake pedal l2 iulcrumed at l3 and held in brake release position by a retraotor spring 9, and the cylinder I0 is connected to conduits l4 not completely shown of a modified form of which in this instance lead to the wheel brake cylinders of the tractor.

The tractor is provided with an electric stop signal circuit controlled by the pressure developed in the master cylinder'and comprises a pressure switch l5 communicating with the pressureside oi the master cylinder and has one contact connected by a conductor 16 to an electric battery 11 grounded -.at l8, and the other contact is connected by a conductor 20 to a stop signal lamp 55 ill grounded at 22. When the brake pedal 1': is

depressed the pressure switch I 5 is closed to energize the stop signal circuit and light the stop 'lamp 2| to indicate that the tractor brakes are applied.

The stop signal circuit is employed to operate an electric magnetic valve 25 whichcontrols'the apparatus for operating the trailer brakes. The control valve is shown in detail in Fig. 4 and comprises a housing 26 having transverseports '21 and 28 communicating with an axial bore 29 connected to a conduit 30 leading to the manifold 3| of the tractor engine for the source of suction. The transverse port 21 is provided with an air breather 32 exposed to the atmosphere, and the transverse port 28 communicates with a power cylinder 33 on the trailer by means of a. conduit 34, coupling 35 and conduit 36. Reciprocally mounted in the bore 29 is a valve'49 having spaced annular closure or valve members 4| and 42 which define an annular recess 43 therebetween to connect the powen cylinder port 28 with the atmosphere port 21 when the valve is in brake release position shown in Fig. 4.

The electro magnetic means for operating the valve is enclosed in a housing 44 bolted-to the I housing of the valve 40 and comprises a solenoid having an annular coil 45 connected to, the stop light signal circuit through a conductor 46, and is ounded as indicated at 4'1. Reciprocally mounted in the'bore 48 of the coil 45 is an iron plunger or core 49 connected to the valve 40 which is normally urged to brake release position by means of a spring 31 interposed between the valve 40 and the coil 45. An adjusting screw 38 is carried by the coil housing 44 and is adapted to be adjusted to alter the travel of the valve 40 inwardly of the coil 45.

The power cylinder 33 is mounted on the axle 50 of the trailer by means of a bracket 20!] and is provided with a port 5| connected to the conduit 36 and has its both ends closed by end plates 52. Reciprocally mounted in the'power or brake cylinder 33 are a pair of pistons 53 spaced apart to define a chamber 54 exposed to the port 5|, the pistons 53 are also spaced from the end plates 52 to define chambers 55 therebetween which communicate' with the atmosphere through ports 56 in the end plates and a breather construction 51 mounted on the end plates 52. Eachpiston is expansible spring 62 which are prevented from displacement by a plate 63 provided with a marginal recess 65 to accommodate the annular retaining ring 6| and spring 62.

Each end plate 52 is provided with an outwardly extending boss 18 in which is fitted an elongated bearing 1| extending a substantial distance into the cylinder 33 for the air tight sliding reception of a piston rod 12 the inner end 13 of which is attached to the piston 53 by means of a nut 14. A brake cable adjusting device is attached to each piston rod 12 by providing each piston .with an elongated axially disposed threaded bore 18 for the threaded reception of one'end of a cable adjusting belt 11 secured to abrake cable 18 extending to the trailer wheel. brake mechanism. The length of each brake cable 18 is adjusted by threading the adjustablebolt 11 with respect to the piston rod 12 and is locked in adjusted position by means of a lock nut 88 adapted to be tightly threaded against the end of the piston rod 12.

A housing is provided to protect the brake cable adjusting device and comprises a sleeve 8I having the end threaded into the bearing 12 and the opposite end is closed by a cap 82 provided with an aperture 83 for the loose reception of the brake cable 18 and with a boss 84 to accommodate the end of the brake cable cover 85.

In order to provide easy access to the nut 88 foradjusting the brake cables 18, each sleeve 8| is provided with oppositely disposed elongated slots 86 for the easy insertion of a wrench to manipulate the nut 88. These openings 86 are covered by flexible covers 81 removably arranged about the sleeves 8| by means of a nut and bolt connection 88.

Each trailer wheel brake mechanism includes an internal expanding brake shoe 98 having separable ends 9| and an anchor pin 92 mounted on an apron 93 which closes the open face of a brake drum not shown attached to the trailer Wheel 89. The toggle mechanism 95 for spreading each brake shoe comprises a pair of toggle arms 96 and 91 pivoted at their outer ends on thrust pins 98 arranged at both ends of each brake shoe; The inner ends of the toggle arms engage a common pivot 99, the inner end of the arm 96 being pivotally connected thereto and the male arm 91 having its inner end bifurcated to permit of both pivotal and sliding connection. In order to prevent the toggle from being pulled over dead center upon inward movement of the brake cable 18, the extreme end I88 of the male arm engages a con necting portion I8I of the female arm 96 and further inward movement of the toggle toward dead center changes the pivot point of the toggle from the axis of pin 99 to the point of contact between the end I88 of the male arm 91 and the connecting portion I.8I of the female arm 96. The

pivot pin 99 is engaged by one end of a link I86 extending through a suitable opening I86 in the apron 93 which is suflicien'tly elongated to permit the link I85 to float back and forth in accordance with the movement of the brake shoe. This link is pivotally connectedat its other end bymeans'of a pin I81 to a lever I88 intermediate the ends thereof. One end of the lever I88 is pivotally connected by a pin I89 to a bracket H8 rigidly secured 'to a housing III mounted on the apron 93. The

other end of the lever I88 is attached to the flexible brake cable 18 by means of a yoke and pivot connection I I2.

The housing III has an open side adjacent the apron 93 and is provided with a marginal flange portion of each housing projects'as at I I1 toward the power cylinder 33 to accommodate a sleeve I I8 in which is slidably disposed the flexible brake cable 18. It will be noted that each housing supports the flexible cable 18 normal to the apron 93,

and that the power cylinder 33 is disposed in align,- ment with each brake cable whereby astraight pull will be exerted on the latter normal to the aprons 93 throughout the length of the brake cables 18 In order to operate the foregoing embodiment assume that the brakes are in release position whereby the stop signal circuit is de-energized and the spring 31 holds the valve in the release position shown in Fig. 4. Under these conditions the piston 53 in the power cylinder 33 will be suspended in' atmosphere since the chambers 55 are at all times exposed to atmosphere, and the chamber 54 is exposed to atmosphere through the conduit 36, coupling 35, conduit 34, annular recess 43 in the valve 25, port 21, and breather 32. When it is desired to apply the brakes, pressure is exerted on the brake pedal I2 to move the hydraulic plunger II into the master cylinder I8 to exert presure on and distribute the brake fluid through the conduits I4 to apply the tractor wheel brakes.

The initial pressure developed in the master cylinder upon braking movement of the brake pedal I2 operates the pressure switch l5 to close the contacts thereby energizing the stop signal circuit to light the signal lamp 2I and thus indicate that the brakes are being applied.

Energization of the stop signal circuit causes energization of the coil which attracts the-iron core-49 to move the valve 48 to brake applied position. In this position the valve 48 connects the chamber 54 of the power cylinder 33 with the engine manifold through the conduit 38, bore 29.

-'port 23, conduit 34, coupling 35 and the conduit levers I88 to pivot about the points I89 and tendsto pull the links I85 outwardly through the slots I86 to flatten the toggles and spread the brake shoes 98 into engagement with the drums to apply the trailer brakes.

In order to release the tractor and trailer brakes,

pressure is removed from the'brake pedal which removes the pressure from the fluid operated tractor brakes and opens the contacts of the pressure switch I5 to de-energiz'e the stop signal circuit which in turn de-energizes the solenoid control valve 25, the spring 31 moving the valve 48 to brake release position to again bring the power cylinder chamber 54 in communication with the atmosphere whereby the pistons 53 are no longer subjected to difierential pressure and tension on the brake cables 18 is released, so that the springs, not shown, in the trailer wheel brakes return the brake shoes 98 to idle position thus collapsing the toggles and returning the brake cables -18 to brake release position.

Another embodiment 'of the invention is illuscylinder is suspended in vacuum when the brakes are in release position. .In this embodiment of the invention the power cylinder I25 is also carried by the axle 50 of the trailer and is in alignment with the trailer wheel brakes I24 so as to effect a straight pull on the brake cables 18 from the wheel brakes to the power cylinder. The power cylinderis provided with a port I26 connected to a conduit I21 extending to a coupling I28 coupled to a conduit I29 leading to the manifold 3|. The ends of the power cylinder I25 are closed by end plates I30 provided with-ports |3| communicating witheach other exteriorally of the power cylinder by means of a conduit I32 connected by a T connection I33 to a conduit I34 extending to a coupling I35 coupled to a conduit I38 leading in this instance to the port 28 of the control valve 25. In this construction the valve bore 29 communicates with the atmosphere through a breather I31, and

the valveport 21 is connected to a conduit I38 Joined to the conduit I 29 and thus to the manifold 3|.

In order to operate this embodiment of the invention, assume that the brakes are in release position. ,Under these conditions the pistons 53' and I34, coupling I35, conduit I36, valve port 28,

recess 43 in the valve 40, port 21 and conduits I38 and I29 to themanifold. 3|. To apply the brakes, pressure is exerted on the brake pedal I2 to distribute liquid under pressure through the conduits I4 to apply the tractor wheel brakes, and also to close the pressure switch I5 which energizes the stop signal circuit and the coil 45 'in the control valve 25 to attract the core 49 and move the valve to brake applied position. In this position the valve 40 interrupts communication between the valve ports 21 and 28 and thus communication between manifold 3| and the end chambers 55 of the power cylinder I25, the latter being exposed to atmosphere through the ports I3I, conduits I32 and I34, coupling I35, valve port 28, bore 29 and breather I31. The pistons 53 are now subjected to a difierential pressure of vacuum in the chamber 54 and atmosphere in the chambers 55 which causes the pistons 53 to move inwardly of the power cylinder I25 and to exert a straight pull on the brake cables throughout their length to flatten out the toggle mechanism in the manner hereinbefore described to efiect braking of the trailer brakes.

When it is desired to release the brakes, pressure is removed from the brake pedal 9 to release the tractor brakes and open the pressure switch I5 which de-energizes the coil 'of the control valve 25, the valve spring 31 moving the valve 40 to brake release position to exposethe end chambers of the power cylinder. I 25 to suction in the manifold 3| suspending the pistons 53 in vacuum whereby the springs, not shown in the trailer brakes, will exert a pull on the brake cables 18 to move the pistons 53 outwardly with respect to the power cylinder I25 to their brake release position.

It will be understood that various changes in the construction and arrangement of parts may be the appended claims.

circuit including a stop signal lamp, power means for operating the vehicle brake, and electromagnetic means connected to said stop signal circuit and rendered operative upon energization of said stop signal circuit to cause operation of said power means to operate said brake.

3. In an automotive vehicle brake system, an electric circuit and a switch for opening and closing said circuit, a stop signal lamp in said circuit, a brake pedal for closing said switch upon depression of said pedal .to brake applying position to energize said circuit and light said signal lamp, a brake for said vehicle, means for operating said brake, and electro-mag netic means connected to said circuit and energized upon energization of said circuit to operate said brake operating means to thereby apply said brake.

4. In a tractor-trailer brake system, a hydraulically operated brake ,for said tractor, a power operated brake for said trailer, a stop signal circuit including a pressure operated switch, a stop signal lamp in said circuit, operator operated means for developing hydraulic pressure to apply said hydraulically operated brake and close said pressure operated switch to energize said circuit and light said signal lamp, and electro-magnetic means connected to said stop signal circuit energized upon energization of said stop signal circuit to effect operation of said power brakes on said trailer.

.5. In an automotive vehicle brake system, an

electric stop signal lamp circuit and a switch therein, a stop signal lamp in said circuit, a brake pedal movable to brake applying position for clos- .6. In an automotive vehicle brake system, a,

.hydraulically operated brake for said vehicle, a

hydraulic cylinder connected in said hydraulic brakes, a' piston therein, operator operated means for applying pressure to said piston for the operation of said hydraulic brakes, a stop signal circuit, a stop signal lamp in said circuit, a pressure switch operated by the pressure developed in said cylinder during braking of said hydraulic brakes to energize said circuit to light said signal lamp, a mechanical brake for said vehicle, a power cylinder, piston meansu'n said power cylinderconnected to said mechanical brake, valve means for establishing difierential pressure on the opposite sides of said piston means to operate said mechanical brakes, and electro-magnetic meansconnected to said stop signal circuit and energized upon energization of said circuit to operate said valve 4-, 2,228,631 means and effect power operation of said me- 8. In a vehicle having a signal and a brake, a 'chanicalbrake. power cylinder with a pressure operated piston 7. In an automotive vehicle brake system, a therein for operating said brake. a valve for conbrake, a power cylinder and piston to operate said trolling pressure to said piston, and means conbrake, an electrically operated valve for controlling necting the signal and the valve for operating 5 the operation of said piston, an electrically operthe valve upon operation or the signal to admit ated signal, and a stop signal circuit for conpressure to said piston for power operating said trolling the operation of said signal and said elecbrake. trically operated valve to cause actuation of said GERHARD C. R. KUIPER.

1o brake upon operation of said signal. 10 

